Gas and liquid contact apparatus



R- s. GAUGLER 2,466,541

GAS AND LIQUID CONTACT APFARATUS April 5, 1949.

Filed Nov. 17, 1945 e Sheets-Shec 1 April 1949- R. s. GAUGLER 2,466,541

GAS AND LIQUID CONTACT APPARATUS Filed Nov. 17, 1943 8 Sheets-Sheet 2 KEY To Fuss. 14 2- AMMONIA Vmm VS HYOROQEM V 2 J t EN April 1949- R. s. GAUGLER 2,466,541

GAS AND LIQUID CONTACT APPARATUS Filed Nov. 17, 1943 8 Sheets-Sheet 3 IIIIIII'I IIIIIIIII,

": rllllllllllllllllllll A: "In", BY: j NVENTORi April 5, 1949.

R. S. GAUGLER GAS AND LIQUID CONTACT APPARATUS 8 Sheets-Sheet 4 Filed NOV. 17, 1943 IN VEN TOR.

April 5, 1949- R. s. GAUGLER 2,466,541

GAS AND LIQU'ID' couuc'r' APPARATUS 8 Sheets-Sheet 5 Filed NOV. 17, 1943 IgVENTOR. V Mfl P 5, R. s. GAUGLER 2,466,541

GAS AND LIQUID CONTACT APPARATUS Filed Novfl'Y, 1943 8 Sheets-Sheet 6 April 5, 1949- R. s. GAUGLER 2,466,541

GAS AND LIQUID CONTACT APPARATUS Filed Nov. 17, 1943 8 Shets-Sheet 7 IN VEN TOR.

April 1949- R. s. GAUGLER 2,466,541

GAS AND LIQUID CONTACT APPARATUS Filed Nov. 17, 1943 8 Sheets-Sheet 8 I 493 5 4144. In Y 5'" J :NVENTOR. Y

Patented Apr- 1949 I I GAS AND LIQUID CONTACT APPARATUS Richard S. Gaugler, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application November 17, 1943, Serial No. 510,587

3 Claims. I

This invention relates to gas and liquid contact apparatus such as may be used in absorption refrigeration apparatus and many other applications.

It is an object of my invention to provide an 5 4-4 of Fig. 3, showing one form of matted wire apparatus capable of improving gas and liquid structure in cross-section; contact in. absorption refrigerators. Figs. 5 to 11 inclusive are transverse sectional It is another object of my invention to provide views of an absorber tube similar to that shown means by which a liquid may have a large surin. Figs. 3, 4 and 12 showing various other forms face exposed to gas and yet be housed within a of matted wire gas and liquid contact apparatus} small space. Fig. 12 is a sectional view taken along the'line It is another object of my invention to provide l2--l2 of Fig. 3; an improved gas and liquid contact apparatus Fig. 13 is a sectional view of an absorber tube by which the various forms of wire material casimilar to that shown in Figs. 3 to 12 inclusive, pable of being manufactured upon a commercial showing another form of wire screen gas and scale may be readily formed to .provide large liquid contact apparatus; liquid surfaces in contact with gas. Fig. 14 is a chart giving the key to the flow It is another object of my invention to provide arrows used in Figs. 1 and 2;

a gas and liquid contact apparatus in an ab- Fig. 15 is-a sectional view of another form of sorber whereby different rates of diffusion of the absorber showing a method and apparatus which gases aid in providing improved absorption and may be used to carry the liquid from one gas separation of the refrigerant and inert gas. and liquid contact apparatus to another;

It is another object of my invention to. pro- Fig. 16 is a sectional view taken along the line vide a fractionator and/or an improved absorber Iii-l5 of Fig. 15 for absorption refrigerators which will be more Fig. 1'1 is a sectional view taken along the line efllcient and smaller. l'l-Il of Fi 15;

It is another object of my invention to pro- Fig. 18 is a sectional view taken along the line vide a horizontal or slightly inclined wire screen l8l8 of Fig. 15; structure capable of holding a thin liquid film Fig. 19 is a sectional view taken along the line exposed on both sides to gas. Ill-49 of Fig. 2;

These objects are attained by providing a .gas Fig. 20 is a sectional view taken along the line and liquid contact apparatus in. the form of 2ll-20 of Fig. 2; matted wire, such as wire screen by which the Fig. 21 is a fragmentary sectional view someliquid may flow to all parts of the matted wire what similar to Fig. 19 showing a modified form and be held therein while the gas is caused to 5 of fractionator; flow along or through the matted wire. Such Fig. 22 is a horizontal sectional view of a rean arrangement may be used in the absorber in ceiver and fractionator tank containing a modia fractionator and also in the evaporator of an fied form of fractionator assembly taken along absorption refrigerating apparatus as well as the line 22-22 of Fig. 23; many other applications requiring intimate con- Fig. 23 is a sectional view taken along the line tact between liquid and gas. 23-23 of Fig. 22;

Further objects and advantages of the present Fig. 24 is a horizontal sectional view through invention will be apparent from the following dea receiver and fractionator tank containing anscription, reference being had to the accompanyother modified form of fractionator assembly ing drawings, wherein a preferred form of the taken along the line 24-24 of Fig. 25; present invention is clearly shown. Fig. 25 is a sectional view taken along the line In the drawings: 25-25 of Fig. 24;

Fig. 1 is a view of an absorption refrigerating Fig. 26 is a horizontal sectional view of a resystem, partly diagrammatic, disclosing one form ceiver and fractionator tank containing another of my invention; modified form of fractionator assembly taken Fig. 2 is a sectional view of the generator. realong the line 26-26 of Fig. 27; ceiver and fractionator, togetherwith a chart Fig. 2'7 is a sectional view taken along the line indicating the meaning of the various arrows 21-21 of Fig. 26; used in Figs. 1 and 2 to show the flow of liquids Fig. 28 is a sectional view taken along the line and gases; 28-28 of Fig. 27;

'2 Fig. 3 is an enlarged sectional view of the absorber used in Fig. 1 taken. along theline 3-3 of Figs. 4 and 12;

Fig; 4 is a sectional view taken along the line Fig. 29 is a horizontal sectional view of a receiver and fractionator tank containing another modified form of fractionator assembly taken along the line 28-28 of Fig. 30;

l'lg.30isasectionalviewtakenalongtheline I88l of Fig. 29; and

Fig. 31 is a sectional view taken along the line 8 l-tl of Fig. 29. p

In Fig. 1, there is shown an absorption refrigerating system provided with a generator 80 heated by a gas burner 8| which drives 08 the refrigerant such as ammonia in vapor form from the liquid in the generator. This vapor is conducted through a vapor tube 82 to a combined receiver and fractionator 34 from which the vapor is conducted upwardly through the conduit 38 to the condenser 88. The condenser 88 has one particularly unusual feature in that the bottom two horizontal tubes 80 are larger to allow more room for the condensed liquid. the vapor and any inert gas which may collect therein. I find by making the tubing in the lower portion of the condenser 38 larger than the tubing of the upper portion that the efiiciency of the condenser is increased.

The liquid refrigerant which is condensed in the condenser 88 flows directly into the inclined tubular portion 82 of the evaporator through which the liquid refrigerant fiows downwardly to and covers the extreme bottom part of the horizontal portion 44 of the evaporator which is formed into a serpentine shape. Hydrogen through the hydrogen supply tube it enters the .serpentine portion of the evaporator 44 at the opposite end and flows above and in the opposite direction to the flow of liquid refrigerant throughout both portions of the evaporator. The liquid refrigerant throughout the evaporator evaporates into and difluses into this hydrogen which accumulates more and more refrigerant vapor as it fiows through the entire length of the evaporator. This mixture of ammonia and hydrogen gases is heavier than the hydrogen supplied through the tube 46 and it flows downwardly through the gas tube 48 which extends through the heat exchanger 50 to the lower end of the absorber 52.

The absorber 52 is provided with a gas and liquid contact apparatus 84 in the form of a porous matted wire structure or partition which is kept saturated with weak liquor flowing from the generator 38 through the weak liquor tube 88 which discharges through a distributing slot in the bottom of the tube, as shown in Figs. 1, 3 and 4 onto the upper end of the porous matted wire gas and liquid contact apparatus 54. At the lower end the matted wire is turned upwardly, as shown in 58, to prevent the heavy mixture of diffusion of the two gases through the wire structure ll. This separation is in addition to that accomplished by the absorption of ammonia gas into the weak ammonia solution.

This separation by diffusion makes it possible for the absorber to deliver hydrogen gas of greater purity and rich liquor of higher ammonia concentration, which results in increased overall thermal efilciency. It is not necessary that the partition I4 divide the absorber tube along the center line of the tube 82, but it may follow any other line to divide the tube 82 into two passages provided that the fiow of liquor through the partition from one end to the other is substantially retained. Instead of any form of porous matted wire structure, any other form of porous metal structure or partition having capillary properties may be used, for example, porous sintered metal.

ammonia and hydrogen from taking the upper passage 68, while at the opposite end there is provided a block III to force the mixture to flow from the'lower passage 85 through the matted wire structure 88. In the matted wire structure 54 the weak liquorabsorbs the ammonia from the mixture of hydrogen and ammonia.

One principal function of the absorber is to separate ammonia gas from hydrogen gas 'and to deliver relatively pure hydrogen at the hydroen discharge end of the absorber. In conventional absorbers this is done exclusively by the absorption of ammonia into the weak ammonia solution. It is known that the rate of diiIusion of hydrogen gas through an orifice or a porous partition is far greater than that of ammonia gas through the same partition. My absorber takes advantage of this relatively greater rate of In the. absorption of ammoniaby the weak liquor heat is evolved and this heat is transmitted rich liquor drips of! the lower end of the matted wire structure 84 and collects in the rich or strong liquor tube 85 which extends to the combined analyzer and receiver.

The weak liquor supply tube 88, for the greater portion of its length, extends through the interior oi the rich liquor tube 88 in order to form a suitable liquid heat interchanger 81. This makes it possible for the rich liquor to be delivered to the combined receiver andfractionator 34 at a comparatively high temperature. The hydrogen which remains after the removal of the ammonia from the mixture of gases flows through the passage 88 above the matted wire structure 54 to the lower end of the hydrogen supply tube 48 which connects to the heat interchanger l8. Inasmuch as some water vapor may condense within the condenser 88 and flow along with the condensed ammonia to the evaporator 82, 48, a drain tube 88 connects the lower end of the evaporator with the tube 48 sothat this water may be returned to the rich liquor tube 84, which will return it to the generator 88. This drain tube 88 is provided with a trap to prevent the fiow of gas through it.

Referring now. more particularly to Figs.'2 and 17 to 24, the rich liquor is discharged from the rich liquor tube onto a fractionator assembly 18. This fractionator assembly ll includes a shallow cup-shaped member" which fits tightly within the receiver tank and is provided with an annular shoulder I4 and a slightly dished bottom I8 providedwith struck-out portions II which extend downwardly. The central portion of the member 12 is provided with a flange 88 which fits tightly against the walls of a vertical portion of the weak liquor tube 88. A comparatively fine screen 82 which is round and slightly dished with a hole in the center rests upon the bottom of the shallow cup-shaped member 12. Above the screen 82 is another fine screen 84 which is round and slightly dished upwardly. Its outer edges rest upon the shoulder 18 which raises the screen 84 above the screen 82 so as to provide a passage between these screens. Resting upon the screen 84 is a coarser screen 88, the central portion of which is provided with a flange fitting Also resting upon the shoulder 14 is a sheet metal disc 98 provided with a downwardly turned rim at its outer edge and a central upwardly turned rim'which is spaced from the flange of the upper screen 88, so as to allow room for the passage of gas therebetween. The outer rim of the disc 88 is sufliciently high to space it sufllciently above the upper screen 88 to allow sufllcient room for gas to pass between it and the screen 85. The disc 98 has an upwardly formed portion 92 forming a dam, so that the rich liquor flowing out of the end of the rich liquor tube 84 onto the disc 88 will be caused to flow in a thin sheet all'the way around the disc 38 to a spout 94 which is formed in the inner flange of the disc 98 so that the rich liquor will flow from the spout 94 into the interior of the cup 88. The

bottom edge of the cup 88 is provided with a plurality of apertures 88 which discharge the rich liquor between the screens 84 and 88. This rich liquor runs down within and surrounding the screens to the shoulder 14, thence from the shoulder. 14 onto the screen 82. As more and more liquid flows onto the screen 82 some falls from the screen 82 into the bottom of the receiver 34 keeping the receiver normally filled with rich liquor to the level indicated by the line 88.

This rich liquor flows through the screen I8I guarding the mouths of the vapor lift tubes I83. The mouths of these tubes I83 are held within a block I85 provided in the connecting tube I81 between the receiver 34 and the generator 38. The bottom of the generator 38 is heated by the gas burner 3i and the products of combustion flow upwardly in contact with the sides of the generator. The generator 38 is normally kept filled with liquid up to the level indicated by the line I89, by the vapor lift tubes I83 which receive heat from the liquid in the generator 38 which causes a portion of the rich liquor in the vapor lift tubes to be evaporated causing the vapor lift action. The vapor lift tubes I83 discharge the vapor and liquid onto the baille III which causes the liquid to run down between its corrugated surface and the side walls of the generator, while the vapor rises over the bellshaped baiile II3 and flows into the upper end of the vapor discharge tube. The vapor discharge tube discharges into the side of the receiver tank 34 between the shallow cup member 12 and the and the screen 88, warming the disc 88 above and the liquid on thescreen .88 below, driving oi! more ammonia from the liquid above and below until it reaches the space between the flanges of the disc 88 and the screen 88 whence it is discharged to the upper portion of the receiver tank 34 and flows upwardly through the vapor conduit 38.

In Fig. 19 there is shown a modification of the analyzer in which, instead of stopping the screen 88 short of the edges of the screen 84, both the 7 screens are extended to the shoulder 14 and prosurface 88 of the liquid. The struck-out portion H5 is twisted so as to deflect the hot vapor discharged from the tube 32 into a spiral path around the receiver and fractionator tank 34 amongst the struck-out portions I8. By this procedure some of the heat is taken away from the vapor and this heat is used to drive off some of the ammonia from the surface 88 of the rich liquor as well as from the liquid on the screen 82. fins hot vapor then flows through the four holes I", provided in the center portion of the member I2 and then radially between the screens 82 and 84 contacting the liquid on the screen 82 beneath and the liquid flowing in the opposite direction within and surrounding the screens above.- In so doing the liquid is warmed giving oif ammonia vapor at the expense of water vapor in the gas which is condensed. The enriched gas then passes through the uncovered edge of screen 84 and thence passes between the disc 88 the form of single threads.

vided with apertures 288 in order to allow the gas to pass through.

In the receiver tank 34, the weak liquor tube 55 is not in one continuous piece, but the portion extending vertically from the coil in the bottom of the tank 34 extends upwardly into the vapor conduit 38 and terminates there above the liquid level I89 in the generator 38. The part of the tube .56 which comes out of the rich liquor tube 84 is joined to the vertically extending part of the I form of matted wire structure may be used. Also the wire used in this matted structure may be made of fine stranded wire instead of wire in The wire used in the structure may be provided with a surface which will increase its capillary properties, such as an oxidized surface or an etched surface, or some form of phosphate coating. The matted wire structure 54 may be made up of layers of screen of various mesh sizes or nested or woven wire material, or of wire material packed together in a random fashion. The block 88 used to block the flow of gasthrough the lower passage 85 of the absorber tube 82 preferably is curled or bent over at its upper edge so that it only contacts the top surface of the matted wire structure 54. Otherwise this block 88 will drain the matted wire structure 54 and.

prevent it from being saturated with liquid.

. The matted wire structures shown in Figs. 5 to 11 may be substituted for the type structure shown in Figs. 1, 3, a and 12. In Fig. 5, a screen assembly 2I2 is provided at the top and thebottom of the tubing, but in addition anothensfcreen assembly 2I4 is provided across the middle of the tubing. This screen assembly 2 is likewise made up of coarse wire assembled to fine wire by having the edges of the fine wire folded over the edges of the coarse wire. They are held in spaced relation by a loose wire structure similar to 285 and 2I8. Fig. 6 is substantially like Fig. 5 with the exception that the lower screen assembly is omitted. 1 Instead of the edges of the lower screen being folded over the edges of the upper, the two may be spot-welded together at various points.

In Fig, 7, a sheet of coarse screen wire 2I8 is provided at the top and beneath it and on the inside walls of the tube is provided a fine screen wire structure 2I8 in which the portion directly beneath the coarse screen wire H6 is provided with downwardly extending folds which are corrugated so as to provide a wavy appearance from one end of the tube to the other. With this arrangement the weak liquor is discharged between the coarse and fine screens at the upper end or 7 theabsorbertubeasinl 'imlandthisliquoa' spreads itself out mainly between the two screens at the top and in the downwardly extending folds III which project into the stream of mixed hysufilclent turbulence to increase the amount of.

being packed together properly in the contact between the gas and the liquid. some of I the liquid may run between the fine screen Ill and the walls of the tube down to the. bottom of the tube. This, however, will only take place when the portions between the screens and the folds are fully saturated.

In Fig. 8, the folds 220 are replaced by downwardly extending loops 222 each of which contain a separate roll section 224 of wire screen. In this arrangement also the liquid is held between the coarse screen I" at the top and the fine screen as well as in the loops 222. The gas flows through the tubes or roll section I as well. as through the remainder of the flattened tube providing an extensive area of exposure between the liquid surface and gas. In Fig. 9, a

somewhat similar arrangement i provided, but a space 228 is provided between the upper coarse screen all and the top of the tube so that gas may fiow through this space and contact the upper surface of the liquid. The roll sections 232 of screen wire are more tightly held by. the loops 2 which are necked in at their upper ends so as to provide the more fine screen surface and contact with the coarse screen 2". The fine screen extends around the walls of the tubing. Fig. is somewhat of a compromise between Figs. 8 and 9 and shows smaller roll sections Ill inside the loops I. In each of these structures the portions of the screens lying against the walls are relied upon to transmit the heat of absorption to the walls of the tubing. 1

In Fig. 11, the upper coarse screen III is shown spaced away from the top of the absorber tube so that gas may pass between it and the top of the tube. However, if desired, it may be placed directly in contact with the top wall surface. Directly beneath the coarse screen is a fine screen provided with a number of folds 242 which extend all the way to the bottom of the tube. Small fiared U-shaped strips 243 clamp together the bottom of each of the folds in to provide abarrier preventing the liquid from draining from the folds 242. In this form the fine screen does not extend all the way around the walls of the tubing, but the contact of the bottom of the folds 242 of the fine screen with the bottom of the tube, together with the thinness of the space between the coarse screen and the top of the tubing are relied upon to transmit the heat of absorption to the walls of the tubing. In this form the liquid applied to the screens will fill all the spaces between the contacting screens and between the folds thereof. v a

In Fig. 13, is shown a double deck form of the construction-shown in Fig, 11 to provide more turbulence of the ga and more extensive and more effective liquid surfaces. The upper screen ill is held against the top of the absorber tube. This screen ass rests upon a second screen 281 having downwardly extending folds 2" at regular intervals. These I folds 2 rest upon a third horizontal screen m which in turn rests upon a fourth screen 293 having folds "I at regular in- I 8 tbe'lcreen ill with its folds Ill and the III with its foldslllin one piece. they may madeof a series of invertedw pod stripe screen with their legs held together by welding or by the boot strips lll or merely absorber Inthisconstructiomitiscontemplatedthatthe liquid will be fed onto or between the top screens "land III- to provide a film ofliquid at all points betweenthesescreens as well asin the folds Ill. The liquid will also run frtlnthe folds III onto the screen "I and provide a ilim of liquid extending to all points between the screens Ill and 2" as well as all points in the folds "I. The boot strips 2" will prevent liquid from draining freely fromtherfolds "I onto the bottom of theabsorber tube. some liquid on the bottom of the absorber tube, however, is desirable and may be provided for by omitting a portion of one or more of the boot strips and the boot strips may be cutshort at the lower end of the absorber tube where it is desirable that the rich liquor drain.

In all of these constructions shown in Figs. 3 to 13 the wire screen may be about 40 mesh either of the singlestrand or multi-strand wire and may be coated oretched to give it a better capillary surface. The wire andthe screens may be fastened together by ferro-phosphorus sintering.

In Fig. 15, is shown aconstruction which may be used when the wire screen structure must be in sections, as for example, when the absorber tubing is made U-shaped. In Fig. 15, the tube 2" is provided with a pan Illwithin the absorber tube 2. This pan is provided with a spout 202 which discharges the liquid from the tube 2 onto the p of the screen assembly 2. In'this screen assembly I, the edges of the screen press tightly against the side walls of the tubing as shown in Fig. 16. Instead of having the edge of one of the screens overlapping the other, both screens are folded away from each other and their edges. The liquid passes down between the screens of the screen assembly 2 to the tongue I at the opposite end which touches the bottom of the tube and discharges the absorption liquid thereon. The portion at of the tube 2 is normally provided with a U-bend as well as-a lateral bend so that the second portion of the tube is lower than the first portion. A dam in is provided in the tube 2" so as to cause the liquid to flow through the U tube 212 which feeds the pan!" provided between the second screen assembly I'll. This pan!" discharges between the screens and this liquid then fills the space between thescreens and when saturated with ammonia is discharged,

from the tongue I'll into the rich liquor conduit. In this arrangement the screens may either be placed upon the horizontal center or above or below the horizontal center. I prefer to place the screens slightly above the horizontal center in order that the gas above may be forced to flow more closely to the surface of screens below it. In thisfigureaswellasinanyoftheotherflgures, a coarse screen may be placedabove a fine screen or both screens may be made alike.

Throughout this application the term gas is 3 intended to include gases which are sometimes tervals extending downwardly into flared U- I called vapors and also those that are sometimes called inert gases. Also the term matted wire is intended to include ordinary screen wire as well as wire which is knitted or woven together in any regular or irregular fashion as well as wire which is packed together in random fashion.

In Figs. 22 and 23 there is shown a iractionator assembly which includes the shallow cup member 312 provided with an annular shoulder 314 resting upon an annular shoulder 315 formed in the wall of the combined receiver and fractionator tank 34. Resting upon the shoulder 314 is a fine screen 384 of about 40 mesh which is slightly dished upwardly toward the center. Resting upon the screen 384 is another screen 386 which may be slightly coarser and which has an inner flange turned up about the edge of an inner cup member 388. The outer edge of the screen 386 stops short of the edge of the screen 384 so as to allow gas to pass through the screen 384 between the edge of the screen 386 and the shoulder 314. Above the screen 386 is a sheet metal disc 398 provided with a downwardly turned rim at its outer edge which rests upon the edge of the screen 384 and a central upwardly turned rim which is spaced from the flange of the upper screen 386 so as to allow room for the passage of gas therebetween.

Differing markedly from the fractionator assembly 18, shown in Fig. 2, there is provided above the disc 398 a spiral member 39! preferably cast of sintered iron or formed of some other suitable capillary material. This spiral member includes I an upper horizontal wall 393 which extends between the vertical portion of the tube 56 and the vertical wall of the receiver and fractionator tank 34. Integral with this top wall 393 and extending downwardly from it to the surface of the disc 398 is a spiral vertical partition wall 395 which begins at the spout 394 of the sheet metal disc 398 and spirals outwardly until at a point just beyond the rich liquor inlet tube 64 it meets a flange 391 extending downwardly from the edge of the horizontal portion 393. Y The disc 398 is placed 10 gas, will flow between'the projections 313 and 31! and rise around the vertical section of the pipe 56 into the space between the screen 384 and the pan 312. Here the gas will flow radially outwardly contacting the liquid on the spiral step of the pan 312 beneath, and the liquid on the screen 384 above, in order to drive off moreammonia vapor. The gas will then pass upwardly through the outer uncovered edge of the screen 384 and thence flow radially inwardly between the screen 386 and the bottom of the disc 398. In so doing it will contact the liquid held by the screens 384 and 386 flowing in the opposite direction beneath and will warm thedisc 398 above, after which it will flow between the cup 388 and the inner flange of the metal disc into the spiral passage provided by themember 39!. In the spiral passages 482 and 399 the gas will contact the warmed liquid flowing in the opposite direction on the surface of the disc 398 aswell as the liquid which will saturate the vertical partition wall 395 and the flange 391 as well as the upper horizontal portion 393 in the capillary member 39!. The ammonia will therefore be driven out :from the liquid on both of these members 398 and 39!. After passing twice around the tank 34 the gas will be discharged from the spiral through the opening 484 in the horizontal wall 393 from which point it will pass into the upper part of the receiver and fractionator tank 34 to the vertical tube 36 which connects to the condenser 38. The

from the tube 64 through the apertures 484 and 364 in the member 39! to join the vertical portion with its upper surface at the same level as the bottom of the tube 84, so that liquid will fiow from the tube 64 through an aperture 364 in the flange 391 onto the adjacent portion of the disc 398 and will be directed in a very thin fiat film in a spiral fashion first around the outside passage 399 between the flange 391 and the spiral 395, and thence around the second passage 482 between two sections of the spiral 395 until it reaches the spout 394 where it is discharged into the cup 388. Because of the highly capillary nature of the sintered iron or other capillary material used in the spiral member 39! it will be saturated with the liquid on the disc 398.

The cup 388 is provided with apertures 398 which direct the liquid in between the screens 386 and 384 allowing the liquid to flow to the edge of the screen 384 from which point it drops onto the outer edge of the shallow cup-shaped pan 312. This pan 312 is formed with a step which extends spirally downwardly and has a raised edge portion slightly higher than the rear portion thereof, so that the step will tend to hold liquid in a thin film thereon. This will cause theliquid in a thin film to spiral downwardly on the pan 312 until it reaches the turned down projections 313 which extend into the rich liquor indicated by the level 98, so that heat may travel from the rich liquor through the projections 313 to the pan 312. Projections 31! are turned upwardly so as to support the center of the screen 384 as well as the cup 388.

With this arrangement, the hot gas or vapor from the generator will be discharged through the tube 32 into the space between the pan 312 and the liquid level 98. The gas here will drive off some ammonia. vapor from the surface of the rich liquor and this, as well as the remaining of the tube 56. a

In Figs. 24 and 25 is a modification of the fractionator assembly shown in Figs. 22 and 23. In this form there is shown a shallow lower pan 412 above which are the two dished screens 484 and 486 which rest upon the shoulder 414 which in turn rests upon the shoulder 415 formed in the wall of the tank 34. The pan 412 is generally like the pan 312 excepting that it is provided with wide circular steps with raised edges so that the liquid will flow radially inwardly from one step to another instead of flowing spirally and having spiral steps as in Figs. 22 and 23. The assembly is provided with an inner cup 488 like the inner cup 388 and the disc 498 which is similar to disc 398. Above the disc 498 is a sheet metal plate 49! having a flange surrounding the vertical portion of the tube 56 and an aperture 493 through which the angular section of the tube 56 passes from the tube 65 into the tank 34. Extending between the plate 49! and the disc 498 is a strip'495 which extends around the inner rim of the disc 498 from one side of the spout to the other and then continues along the adjacent'edge of the aperture 493. -Also between the plate 49! and the disc 498 are two sets of two screens. The inner set designated by the reference character 45! consists of two screens having their vertical portions in contact with each other but their lower edges spread to provide flanges which extend radially inwardly and outwardly on the surface of the disc 498. The outer sets of screens 453 are similar and are provided with similar flanges. These two sets of screens 45! and 453 are positioned to divide the space between the partition 495 and the flange of the pan 412 substantially equal.

With this arrangement liquid will flow from the tube 65 onto the disc 498 and, by reason of the partition 495, will be forced to pass once around the disc before it reaches the spout. In passing around the disc it will come into contact with the bottom portion of each of the sets of screens lll and lll and the liquid will rise to form a fllm on each of these sets. At the same time the liquid will cover the top surface of the disc. lll. From the spout of the disc lll the liquid will flow through the apertures 496 of the cup lll and between the screens lll and 486 to the outer edge of the pan "2 and from that point will flow over the steps of the pan "2 to the point where the projections 413 are turned down into the liquid ll.

The hot gas or vapor from the generator will enter the space between the surface of the liquid ll and pan "2. This will heat the liquid ll and cause some of the heat to be transmitted through the Projections "I to the pan "2. The pan 412 will also be heated directly by this vapor. The vapor will then flow upwardly between the pan 412 and the screen lll and also between the screen Ill and the disc lll as explained previously. Thereafter the gas will pass into the space between the disc lll and the plate lll ad- Jacent the spout of the disclll and will pass once around the tank through the passages formed between the disc lll and the plate lll and between the vertical partition lll and the sets of screens lll and lll and the up-tumed flange of the pan "2 untfl it reaches the aperture lll. In so doing it flows in counter-current fashion to the rich liquor flowing from the tube ll which is presented to the gas in a very thin fllm on the disc lll, in order to provide the most intimate contact between the liquid and the gas so that water vapor in the gas will be replaced by ammonia vapor from the rich liquor.

In Fig. 26, there is shown a spiral form of fractionator assembly in which the bottom sheet metal member lll may be cut from a flat sheet of steel with flanges Ill and lll formed on its inner and outer edges and also provided with a radial out and formed into a flat spiral. Fastened to, but spaced above the bottom of the spiral sheet metal member lll is a set of two screens lll and lll which are turned upwardly at their.

edges and fastened by spot-welding or other suitable means to the inner and outer flanges lll and lll of themember Ill. The screens lll and Ill together with the member lll form a lower assembly.

Above this lower assemblythere' is a second assembly which includes a second spiral sheet metal member lll having its edges Ill and Ill bent down and outwardly as indicated. To these edges is fastened, by spot-welding or other suitable means, a second set of two screens Ill and Ill. These screens Ill and Ill have their edgu turned up and fastened to the downwardly turned edges II! and Ill of the flat spiral member Ill. The two spiral assemblies are so arranged that the lower end lll of the upper assembly substantially registers with the upper end lll of the lower spiral. In fact as is better shown in Fig. 28 the bottom end of member lll preferably overlaps the upper end' of the screens Ill and III while the lower end of the screens Ill and Ill overlap the upper end of the screens 12 over the angularly cut endof the tube ll. By this arrangement the rich liquor from the pipe ll will be fed in between the screens at the upper end of the spiral over which point it will flow downwardly between the screens lll and Ill to their lower ends. 'At this point the liquid will be transferred to the upper ends of the screens Ill and Ill from which point it will flow between the screens Ill and Ill to the lower end of their flat spiral. At their lower end this liquid will be discharged onto the upper end of the sheet metal member Ill which is provided with radial grooves Ill to distribute the liquid all over the upper surface of the member Ill.

The centers of the screens lll, lll, Ill and lll may be raised slightly to overcome any possible tendency for the liquid to flow downwardly too fast at their central portions.

The hot gas or vapor from the generator issuing from the pipe ll will pass between the bottom of the sheet metal member lll and the surface ll of the weak liquor to the bottom end lll of the sheet metalmember lll. As shown by the arrows it will ascend the spiral, first passing between the screen lll and the sheet metal member lll, for one turn around the tank ll thereby contacting the liquid in the radial grooves III on the sheet metal member lll as well as contacting the liquid on the bottom of the screen lll, flowing downwardly in counterflow with the gas so that ammonia is driven from the liquid at the expense of the water vapor in the gas. Afterthis gas reaches the upper end lll of the lower assembly it will pass between the screen Ill and the screen lll thereby contacting the liquid in'the screen lll as well 1 member lll'until it the upper end as ll! and lll, while the lower end of the screens Ill and Ill overlap the upper end of the sheet metal member III I A portion of the flange III is cut out as shown in Fig. 28 to receive the angularly cut end lll of the tube ll. .At this particular point the screen Ill is held tigh y against the bottom of. the tube ll whereas thescreen lll is turned up as shown by the reference character l2! and of the upper assembly where it is discharged into the upper portion of the receiver tank and passes to the generator as before.

In Figs. 29 to 31, is another modiflcation which bears some resemblance to the modificationsshown in Figs. 28 to 28. In this modiflcation there is shown a fractionator assembly which includes a lower sheet metal disc lll having an inner flange lll fastened by spot-welding or other suitable means to a sleeve lll mounted upon the vertical portion of the tube ll. The cuter dgeoi'thedisclll isprcvidedwithawide lip-turned flange lll. Above the sheet metal disc lll isadiscformedofanupperscreen Ill and a lower screen lll each having up-turned flanges which are vfastened totbe up-turned flange lll of the sheet metal member lll and the sleeve lll. Above the screen lll is another set of screens lll and lil having up-turned flanges which are likewise fastened to the sleeve lll and the flange lll. Above the screen lll is another sheet metaldisclil having up-turned flange lll and the a 13 other side of the cut is provided with an upwardly turned flange 641 while the screens 6|! and BIS are provided with a downwardly turned flange 649 which overlaps the upwardly turned flange 641 as shown in Fig. 31. The other side of the cut of the screen H and H3 is provided with an upwardly turned flange 65! which is overlapped by the downwardly turned flange 653 of the sheet metal disc 6| l. The other side of the cut may be provided with an upwardly turned flange 655.

The screens H3 and H5 are arranged with the greater capillarity. The openings in the mesh may be increased as its capillarity increases.

flange 649 adjacent the entrance of the tube 64 into the tank 34. These screens H3 and Eli are spread slightly at this point of entrance so that the liquid is fed in between the screens. This liquid will form a fllm between the screens H3 and 615 throughout their area and will then pass by means of the flanges 649 and 641 to the screens 601 and 609 and will form a film between these two screens 60! and 609 throughout their area. The liquid will finally be discharged from the screens 60! and 609 by the flange 645 and the flange 643 of the lower disc 60L This liquid will flow over the entire surface of the disc 6M and flnally be discharged over the flange 64! onto the surface of the liquid 98.

The hot gas or vapor issuing from the tube 32 will pass between the disc 6M and the surface 68 of the liquid giving up some of its heat to both. This heat will drive off some ammonia vapor from the liquid on the disc 6M and some from the surface 98 of the liquid in the tank 34. This hot gas and ammonia vapor will then reach the flange 6 and pass between the flange 6 and the flange 643 to the space between the screen 609 and the disc 61". This gas and vapor .will then pass once around the tank 34 between the screen 609 and the disc 6 where it will contact the liquid on the disc 60! and the liquid on the bottom of the screen 609, each flowing in the opposite direction. After this, the gas will pass between the flanges 645 and 641 to the space between the screens 60'! and 6 l3 where in passing around the tank the second time it will contact the liquid flowing in the opposite on each of these screens. It will then pass between the flanges 649 and 65l and pass again around the tank between the screen M5 and the disc 6H contacting the liquid in the screen 615. It will finally escape between the flanges 653 and 655 into the upper portion of the tank 34 over which it will be conducted to the condenser.

It will be seen that in each of these forms a long liquid path is provided in between the bottom of the tube 64 and the surface of the liquid 96 in which it flows in counterflow fashion to the vapor or gas from the generator. The use of the screens makes it possible for the fllm of liquid to be contacted upon its upper and lower sides by the gas. The bottom sheet metal member insures that the liquid will not be drained from the screen by the splashing from the surface 98 of the liquid in the tank. The upper covering member insures that the gas will be kept in contact with the upper face of the screen and the liquid thereon, so that maximum use of this property is made thereby. The various modifications give a wide choice in methodsof manufacture and different ones or more adaptable to different forms of manufacture and different quantities. In all of them the screens should be about 40 mesh and have a wire size of from .010" to .012". Stranded wire may be used in making the screens in order to provide While the form of embodiment of the invention as herein disclosed. constitutes a preferred form, it is to be understood that other forms might be adapted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. Gas and liquid contact apparatus for transferring a volatile substance between a gas and a liquid comprising a hollow container provided with means forming at least one passage for the flow of gas therein, said means including a wire screen structure extending substantially parallel to the general flow of gas in said passage, said structure having large areas formed entirely by two wire screen portions in continuous direct intimate area contact with each other throughout the large areas and exposed on both their non-contacting sides to the flow of the gas, said contacting portions forming a thin capillary structure capable of holding and conducting such a thin fllm of liquid throughout their contacting area to assure intimate contact between all of the liquid and the gas to assure maximum transfer of said substance, and means for conducting liquid to the wire screen structure adjacent its highest point, said wire screen portions being generally horizontal but slightly inclined downwardly from said highest point, and means for circulating gas in direct contact with and generally parallel to said screen portions beginning at the lowest point thereof.

2. Gas and liquid contact apparatus comprising a hollow container provided with means forming at least one passage for the flow of gas therein, said means including hollow tubular shaped portions extending longitudinally with respect to the general flow of gas, said hollow tubular shaped portions having wall portions formed of two sheet portions of wire screen material in direct area contact forming a capillary structure capable of holding a thin film of liquid, said sheet portions being exposed on their non-contacting sides to the flow of gas, and

. means for filling said capillary structure with a liquid.

3. Gas and liquid contact apparatus for transferring a volatile substance between a gas and a liquid comprising a hollow container provided with means forming at least one generally horizontal passageway for the generally horizontal flow of gas therein, said means including a wire screen structure having large areas extending substantially parallel to the flow of gas in said passageway formed entirely by two freely exposed generally horizontal wire screen portions in continuous direct intimate area contact with each other throughout the large areas to form a thin capillary structure capable of holding and conducting throughout their contacting area a liquid film of such thinness to assure intimate contact between all the liquid and the gas to assure maximum transfer of said substance, said two screen portions being directly exposed on both their non-contactin sides to the flow of the gas substantially parallel to their surfaces to expose to the gas both the upper and lower surfaces of the thin film of liquid, and means for conducting liquid to the wire screen structure to supply the liquid for the formation of the thin fllm upon said two contacting screen portions.

RICHARD S. GAUGLER.

(References on following page) REFERENCES CITED UNITED STATES PATENTS Number v Name Date Parmenter Jan. 18, 1881 Latham Dec. 11, 1900 Talbot May 30, 1905 Hart Oct. 16, 1906 Cox Aug. 13, 1907 Cutter Apr. 18, 1911 Lang July 25, 1911 Winks Oct. 29, 1912 Hughes May 7, 1918 Number Number 16 Name Date Laird June 13, 1922 Jones Apr. 3, 1923 A Fauconnler Nov. 30, 1926 Snowden et al Apr. 4, 1933 McLean Sept. 14, 1937 Schaefer Dec. 9, 1941 Styren Dec. 30, 1941 Hlxley June 2, 1942 FOREIGN PATENTS Country Date Germany Mar. 26, 1917 Great Britain Jan. 7, 1926 Great Britain July 14, 1941 

